10 Vaccine Myths—Busted

Sitting through your baby's immunization-induced
meltdown can be as painful for you as it is for her.
That is, if the nagging worry that these routine
shots could do more harm than good doesn't get to
you first. No wonder a recent study from the
University of Michigan found that 93 percent of
pediatricians had at least one parent who refused a
vaccination for their child during the past
year.

Why are vaccines under fire? Some experts say
it's due to their success. "It's the natural
evolution of a vaccine program," says Paul Offit,
M.D., chief of infectious diseases and director of
the Vaccine Education Center at the Children's
Hospital of Philadelphia. "As you eliminate the
diseases, people are not as compelled to get
vaccines." Adds Kathryn Edwards, M.D., spokesperson
for the National Network for Immunization
Information, "Many diseases are out of sight and
then out of mind. So people don't see the value of
vaccines."

Yet high immunization rates are necessary to keep
diseases like measles and even polio from making a
dangerous comeback. Here are ten myths about
vaccines—and the truth behind them.

No doubt about it, the immunization schedule
recommended by the Centers for Disease Control and
Prevention and the American Academy of Pediatrics
(AAP) can seem daunting. Your child can receive up
to 23 shots by the time she's 2 years old and as
many as six shots at a single doctor visit. So it's
not surprising that many parents have concerns about
how vaccines might affect a child's developing
immunity and often cite these as a reason to refuse
a vaccine.

But it should be the least of your worries.
"Children have an enormous capacity to respond
safely to challenges to the immune system from
vaccines," says Dr. Offit. "A baby's body is
bombarded with immunologic challenges—from bacteria
in food to the dust they breathe. Compared to what
they typically encounter and manage during the day,
vaccines are literally a drop in the ocean." In
fact, Dr. Offit's studies show that in theory,
healthy infants could safely get up to 100,000
vaccines at once.

The bottom line: It's safe to give your child
simultaneous vaccines or vaccine combinations, such
as the five-in-one vaccine called Pediarix, which
protects against hepatitis B, polio, tetanus,
diphtheria and pertussis (also known as whooping
cough). Equally important, vaccines are as effective
given in combination as they are given individually.

Myth 2: As long as other children are getting
vaccinated, mine don't need to be.

Skipping vaccinations puts your baby at greater
risk for potentially life-threatening diseases. "The
ability of immunizations to prevent the spread of
infection depends on having a certain number of
children immunized," says Thomas Saari, M.D.,
professor of pediatrics at the University of
Wisconsin Medical School in Madison. "Scientists
refer to this as 'herd immunity.' Unfortunately, the
level of immunization required to prevent diseases
such as measles from spreading from child to child
is high—95 percent." In 2003, the national
vaccination rate in children ages 19 to 35 months
was only about 80 percent—though that number
increases to the mid-90s when children reach school
age.

These rates may not be high enough to provide
herd immunity, especially as exemptions from school
vaccines are on the rise. In studies from Colorado,
where residents claim high numbers of vaccine
exemptions for medical, personal and religious
reasons, kids who are not immunized are at greater
risk for disease. Case in point: They're 22 times
more likely to come down with measles.

Myth 3: Now that major illnesses have largely
disappeared, we really don't need vaccines anymore.

Don't bet on it. Despite our relatively high
vaccination rates in the U.S., many American
communities still have outbreaks of diseases like
measles and pertussis, a respiratory illness
characterized by spasms of coughing that can last
for weeks or even months. In 2003, 13 children died
of the infection.

Unvaccinated children can also spread infection
to vulnerable family members. "Those children are
more likely to give a disease to those who can't
fight it off, such as a six-month-old or a
grandparent living at home," says Dr. Saari. The
incidence of whooping cough has been increasing
since 1980, and the Centers for Disease Control and
Prevention recently recommended a pertussis booster
shot for 11-year-olds because the risk of passing
the disease to a vulnerable relative is so high.

What's more,
diseases
are spread by people from foreign countries who
travel here. "Air travel has extended the range of
diseases from countries where people aren't
immunized," says Dr. Saari. "We're no more than one
airplane ride from being exposed to many diseases."

Myth 4: Vaccines cause autism and other
disorders.

Concerns about a link between a combination
vaccine for measles, mumps and rubella—called the
MMR vaccine—and the developmental disorder autism
got kicked up by a case report from England seven
years ago. But it has been roundly discredited. The
notion has persisted because autism tends to emerge
around the time that the vaccine is given—when a
child is a year old. Experts stress, however, that
this does not mean the vaccine caused the problem.
"Not only is there no evidence that it causes
autism, there's evidence that it doesn't cause
autism," Dr. Offit says. "In fact, there have been
14 studies that show your risk of getting autism
isn't any different if you got the MMR vaccine or if
you didn't."

The Institute of Medicine backed up that
conclusion in a report issued last summer. Worries
linger, Dr. Offit adds, because "it's hard to unring
the bell. People reasonably assume that if there is
nothing to it, why was there so much smoke?" Parents
have expressed similar fears about vaccines and the
incidence of sudden infant death syndrome (SIDS).
"Numerous vaccines are given to little babies over
that first year, just when a lot of developmental
changes are occurring," says Dr. Edwards. "If
something happens around the time a
vaccine
is given, it's easy to think the vaccine caused it."

Myth 5: My baby might get the disease it's
supposed to prevent.

"Most vaccines we give today, such as meningitis
and DTaP, contain killed vaccines—not live agents
that could replicate," says Dr. Edwards.

That's true of the scariest diseases doctors
vaccinate against, such as polio, which was once
made with live weakened polio virus. Until this type
of vaccine was phased out, around 1994, a tiny
fraction of people—one in 2.4 million—contracted
polio from the vaccine itself. But since then,
children in the U.S. have received polio vaccine
made from killed virus, so there's no risk of
contracting the disease from the shot. A few
vaccines that are on the schedule do, however,
contain live weakened virus to provoke an immune
response. These include the MMR and chicken pox
immunizations. "These vaccines have the potential to
cause some mild illness—a little fever and rash,"
explains Dr. Edwards. "But the illness is much less
severe than if a child naturally contracted measles
or chicken pox."

Myth 6: Vaccines can contain preservatives that
are dangerous.

Until recently, many vaccine concerns centered on
the safety of thimerosal, a compound that prevents
the vaccine from being contaminated by bacteria and
contains a form of mercury called ethylmercury.
Mercury in large quantities is known to be harmful
to a child's developing brain. Worries about
thimerosal's effect on children prompted its removal
from nearly all childhood vaccines in 1999. (Thimerosal
is still present in some flu vaccine—though you can
ask your doctor for a thimerosal-free shot.)

Yet it's become clearer since then that
ethylmercury does not pose the same health hazard as
its cousin, methylmercury, a metal found in the
environment that's known to accumulate in the body
and cause harm to developing children. "The body is
able to eliminate ethylmercury much more quickly
than it can eliminate methylmercury," says Dr. Offit.

University of Rochester researchers confirmed
that when they compared mercury concentrations in
the urine, blood and stools of children who got
vaccines containing thimerosal with those of kids
who received only thimerosal-free vaccines. All the
children had mercury levels well below the EPA's
most stringent public safety limits.

Even if your baby received a vaccine that
contained thimerosal, the overwhelming majority of
data support a lack of association between the
substance and neurological problems, says Margaret
Rennels, M.D., the chair of the committee on
infectious diseases of the AAP, who points out that
children are exposed to mercury from many
environmental sources. "The reality that a lot of
people seem to miss is that the largest source of
organic mercury is the environment: the air we
breathe, the water we drink and the fish we eat.
That's due to the burning of coal," she says. You
can lessen your child's mercury exposure by limiting
the amount of fish she eats. The Food and Drug
Administration says that it's safe for young
children to eat albacore tuna once a week and fish
that are lower in mercury (such as "chunk light"
tuna, pollack, salmon, and catfish) twice a week.
(Shark, swordfish, king mackerel and tilefish, which
have high mercury levels, are off the menu.)

Myth 7: You shouldn't give a vaccine to a child
who has a cold.

It's reasonable to think that a sick child would
be more likely to have a bad reaction to a vaccine
or that it might present an added burden to her
immune system if she's fighting off a cold. Yet
studies show that having a mild illness doesn't
affect a child's ability to react appropriately to
the vaccine.

"Certainly if a child comes in with a fever of
102 and a rip-snorting ear infection, it's not the
best time for a vaccine," says Dr. Rennels. "But a
low-grade fever, mild respiratory infection or a
little diarrhea shouldn't be reasons to delay one,
especially if the illness is on the way out."

Of course, vaccines can themselves trigger side
effects, including fever and rash, as well as
soreness at the site of the injection, but these are
rarely cause for alarm. The five-in-one Pediarix is
more likely to cause a low fever than the individual
shots are, but many moms say the fewer injections
for their child, the better. Call your doctor right
away if your child has hives (which can indicate an
allergic reaction), a fever of 105 degrees or
higher, or convulsions.

Myth 8: I had chicken pox when I was a kid and
it isn't a big deal.

Like several common childhood diseases, chicken
pox isn't a big deal for most kids. "But on rare
occasions children can die from it," Dr. Rennels
observes.

Before the vaccine was introduced, many children
were hospitalized each year with serious
complications, including pneumonia and dangerous
skin infections. "Chicken pox lesions can become
infected with staph, including necrotizing
fasciitis—the 'flesh-eating' bacteria," says Dr.
Rennels. Getting the vaccine is especially important
now that less of the chicken pox virus is in
circulation. "Children who don't get chicken pox or
the vaccine are at risk of getting it as an adult,
which is a much more serious illness."

Myth 9: Vaccines can provide 100 percent disease
protection.

Not quite. The best vaccines are those made with
live weakened virus, such as MMR and chicken pox,
which are about 95 percent effective. The
effectiveness of vaccines made with killed, or
inactivated, virus is between 75 and 80 percent.
That means there's a chance you could be vaccinated
against a disease and still get it. But, says Dr.
Edwards, if all children are vaccinated against an
organism, it's less likely to hang around. That's
why vaccinating an entire population is so
important. "Not getting vaccinated is like failing
to stop at a four-way stop," Dr. Edwards says. "If
three people get vaccinated but one doesn't, the
risk is not bad. But if two people don't get
vaccinated, the burden of risk is greater on
everyone."

Myth 10: It's best to wait until children are
older before starting to give them vaccines.

Immunization schedules are designed to protect
the most vulnerable patients from disease. If you
wait to give the vaccine, you may miss the window
when a child is most vulnerable. "When you get off
the schedule, you really put your child at risk,"
Dr. Saari says.

Case in point: Last year in Wisconsin 300
children under age 1 came down with whooping cough,
177 of them less than 6 months old. Of these, half
were hospitalized and three died. Yet, says Dr.
Saari, "for a child to die from whooping cough in
this day and age is criminal."

As our readers know, wesupports parents'
rights to make up their own mind about how to raise
their kids. We try our hardest to avoid using the
word "should"—except when it comes to safety. You
should put your baby to sleep on her back,
you should strap her into her car seat and,
yes, you should make sure she gets every
vaccine on the schedule